Technical Interview: Electronics and Communication Engineering

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Electronics and Communication Engineering

Electronic Devices and Circuits

1) Define band-gap energy. What is the relation between and temperature?

2) What is Fermi-Dirac function?

3) Define mean lifetime of a carrier: hole or electron.

4) What is continuity equation?

5) Can you mention any one application of Hall Effect?

6) Define hole in a semi-conductor.

7) Write down the expression for current in a p-n junction diode.

8) What are transaction and diffusion capacitances of a p-n diode?

9) What is the difference between static and dynamic resistance of a diode?

10) What is the specialty of Zenere diode?

11) What is the application of tunnel diode?

12) What is ripple factor?

13) Mention ripple factor and regulation of: Half wave rectifier; Full wave rectifier, Bridge rectifier C – filter; PI filter.

14) What is meant by regulation in a power supply?

15) What is clipper?

16) What is clamper?

17) What is Ebers-Moll equation of a transistor?

18) What are the different regions of operations of a transistor?

19) What are the different regions of configurations of a transistor?

20) Why does a transistor need biasing?

21) Define stability factor.

22) Mention the merits and demerits of various bias circuits.

23) What is thermal runaway?

24) Define H – Parameter model of transistor.

25) What is small signal model of a transistor?

26) What is the specialty of high frequency model of a transistor?

27) What is phase reversal in Common Emitter configuration of transistor?

28) Why is common collector circuit known as emitter follower circuit?

29) Why is RC coupling most widely used coupling between two-stages of a cascaded amplifier?

30) What is push pull amplifier?

31) Define gain and phase margins of an amplifier.

32) What is tuned amplifier?

33) List out advantages of a Field Effect transistor.

34) What is Uni-junction transistor?

35) Classify the transistor-based amplifiers.

36) What is feedback amplifier?

37) What is LED/LCD?

38) What is opto-coupler?

39) What are the Barkhausen՚s conditions for oscillations?

40) What is Wein bridge oscillator?

41) List out the characteristics of an ideal operational amplifier.

42) Define: CMRR, slew rate, offset voltage, and currents

43) What is virtual ground?

44) What are bi-stable, mono-stable and astable multi-vibrators?

45) How does square waveform differ from pulse waveform?

46) What is Miller sweep circuit?

47) What is meant by time base?

48) What is monolithic IC?

49) What is an instrumentation amplifier?

50) What is a difference between triangular and sawtooth waveforms?

51) What is voltage-controlled oscillator?

52) What is phased locked loop?

53) Can you explain any one three pin regulator?

54) What is UPS?

55) What is the working principle of IC 555?

56) How can an RC network circuit be used as integrator?

57) How can an RC network circuit be used as differentiator?

58) What is double differentiator?

Communication Systems

59) Why do we need modulation?

60) What is the Band Width used for TV broadcasting?

61) What is the Band Width required for Speech signal transmission?

62) What is ‘auto correlation’ and ‘cross correlation’ ?

63) What is the figure of merit for modulation with Full Carrier, Double Side Band Suppressed Carrier, and Single Side band modulation?

64) What are the disadvantages of amplitude modulation?

65) What is the band width required for Frequency Modulation transmission?

66) Define entropy.

67) State Shannon theorem.

68) Why do you need aliasing filter for PCM before sampler?

69) How is Differential Pulse Code Modulation different from Pulse Code Modulation different from Pulse Code Modulation?

70) Define bit error rate.

71) Mention the bit error rates for Amplitude Shift keying, Frequency Shift Keying and Phase Shift Keying.

72) What is channel capacity?

73) What is mean by multiple access techniques?

74) Which method of multiple access technique is used for Global System for Mobile communication?

75) Which method of multiple access technique used for satellite communication?

76) What is the principle of Code Division Multiple Access (CDMA) transmission?

77) How do you analyze the performance of analog communication system?

78) How do you analyze the performance of digital communication system?

79) What is mean by Envelope Distortion in Amplitude Modulation and Demodulation?

80) Why is PLL used?

81) What is mean by half duplex communication?

82) What is mean by simplex communication?

83) What is mean by full duplex communication?

84) How do you decide number of bits required to represent a sample in Pulse Code Modulation?

85) What is quantization noise?

86) How does signal to quantization noise ratio depends on number of bits of a sample?

87) How do you get Frequency Modulation wave from Phase Modulation Modulator?

88) How do you Phase Modulation wave from Frequency Modulation modulator?

89) What is the functionality of matched filter?

90) What is capture effect?

91) What is super-heterodyne receiver?

92) What is image frequency in super-heterodyne receiver?

93) What are the factors considered for the selection of Intermediate frequency?

94) What is the frequency of Amplitude Modulation broad casting?

95) What is the Frequency used for Frequency Modulation broad casting?

96) What is the Intermediate Frequency used for Frequency Modulation broad casting?

97) What is the Intermediate Frequency used for Amplitude Modulation broad casting?

98) What is Vestigial Side band? What is its significance?

99) What type of modulation is used for audio in Television broad casting?

100) Define modulation index.

101) What are pre-emphasis and de-emphasis?

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